He does it after hours. Helping someone out with mental issues and keeping him stable ( he is a good employee after all), might not be the worst decision :) If

He does it after hours. Helping someone out with mental issues and keeping him stable ( he is a good employee after all), might not be the worst decision :) If you're going to get rid of every employee with issues, you shouldn't hire anyone. Social affairs are the most difficult in being an employer, for this person in particular a stable "relation" might improve things. He obviously has more than normal issues, but he's still a good employee who accomplished a lot in a short time. Also notice that the op didn't mention the option to fire him. So the only other way is to "help him".